Compile IMX_SDMA as a module

Change-Id: Ibd66790701d52a6128b2cdc6eed76bacee1e0c61
diff --git a/debian/defconfig b/debian/defconfig
index b3e7e96..289e505 100644
--- a/debian/defconfig
+++ b/debian/defconfig
@@ -131,3 +131,5 @@
 CONFIG_GPIO_PI4IOE5V6408=m
 CONFIG_TPU_AKIRA=m
 CONFIG_YORKTOWN_TPU=m
+
+CONFIG_IMX_SDMA=m